DefinitionA person who murders 3+ people over a period of > 30 days, with a “cooling off” period between each murder, and whose motivation for killing is largely based on psychological gratification.

Typical profile Arson tendencies, compulsive, drug and/or alcohol-abusing parents, often victims of cruel parenting, often the result of a difficult or unwanted pregnancy, evidence of biochemical and/or genetic defects, history of sexual assault, drug or alcohol abuse, cruelty to animals, interrupted/absent “bliss of childhood”, pathological lying, sexual deviancy, suicidal tendencies, ritualistic behaviours, search for help and/or feel powerless to prevent killing, may have a history of perinatal head trauma, severe memory disorders. Serial killers usually wear masks of sanity.

The killings often have a sexual element, are stylistically similar to each other and the victims have something in common–e.g., occupation, race, appearance, sex, or age group. Serial killers are not the same as mass murderers, who commit multiple murders at one time; nor are they spree killers, who commit murders in two or more locations with virtually no break in between. Most authors exclude terrorists and contract killers from their definitions of serial killers.

Name…period of activity…number of victims

Jack the Ripper 1888-91…5-11 victims (uncertain)

Albert DeSalvo, aka Boston Strangler 1962-64…13 victims

David Berkowitz, aka Son of Sam 1975-77…6 victims

John Wayne Gacy mid-1970s…33 victims

Ted Bundy 1974-79…23 victims

Jeffrey Dahmer 1978-1991…17 victims

Andrei Chikatilo–Russia 1978-1990…53 victims

Harold Shipman–UK doctor 1980s-1998…250 victims (estimated)

In the working parlance, serial killers are understood to have a substrate of mental illness for which killing serves to relieve internal stress. It can be difficult to distinguish the ‘sick’ killers from the ‘normal’ killers, for whom

(1) it’s just another job–e.g., a hit man like Richard Kuklinski (the “Ice Man”), or

(2) it’s an expedience–e.g, Harold Shipmen, the GP in the UK whose victims were “cash cows”–once the little bitties he tended changed their wills, naming him as beneficiary, Poof!